Low-Frequency Oscillations in Optical Measurements of Metal-Nanoparticle Vibrations

Autor:	Aftab Ahmed, Rachel Gelfand, S. David Storm, Anna Lee, Anna Klinkova, Jeffrey R. Guest, Matthew Pelton
Rok vydání:	2022
Předmět:	Mechanical Engineering Metal Nanoparticles General Materials Science Bioengineering Gold General Chemistry Condensed Matter Physics Vibration
Zdroj:	Nano Letters. 22:5365-5371
ISSN:	1530-6992 1530-6984
DOI:	10.1021/acs.nanolett.2c01339
Popis:	Time-resolved optical measurements of vibrating metal nanoparticles have been used extensively to probe the ultrafast mechanical properties of the nanoparticles and of the surrounding liquid, but nearly all investigations so far have been limited to the linear regime. Here, we report the observation of a low-frequency oscillating signal in transient-absorption measurements of nanoparticles with octahedral gold cores and cubic silver shells; the signal appears at the difference of two mechanical vibrational frequencies in the particles, suggesting a nonlinear mixing process. We tentatively attribute this proposed mixing to a nonlinear coupling between a vibrational mode of the nanoparticle and its optical-frequency plasmon resonance. The optimization of this nonlinear transduction may enable high-efficiency opto-mechanical frequency mixing in the GHz-THz frequency regime.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1f67c46e9ae5da0e9feb2b8f9a12bd0c https://doi.org/10.1021/acs.nanolett.2c01339 Zobrazit plný text záznamu